diff --git a/drivers/md/bitmap.c b/drivers/md/bitmap.c
index c1f28a8..b1bcd36 100644
--- a/drivers/md/bitmap.c
+++ b/drivers/md/bitmap.c
@@ -1695,6 +1695,7 @@
 	mddev->bitmap = bitmap;
 
 	mddev->thread->timeout = mddev->bitmap_info.daemon_sleep;
+	md_wakeup_thread(mddev->thread);
 
 	bitmap_update_sb(bitmap);